Filtry
wszystkich: 1150
wybranych: 1056
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: TRANSMISSION SHAFT
-
Structural Health Monitoring of Overhead Power Transmission Lines
PublikacjaStructural Health Monitoring (SHM) is a novel and continuously developing branch of science and technology that draws attention of scientists all over the world. It creates opportunities to detect, localize and identify structural damage of various types such as: line breakage, permissible sag, bolt loosening, fatigue cracking or insulator contamination. On the other hand the methods used to estimate the remaining operational...
-
The secure transmission protocol of sensor Ad Hoc network
PublikacjaThe paper presents a secure protocol of radio Ad Hoc sensor network. This network operates based on TDMA multiple access method. Transmission rate on the radio channel is 57.6 kbps. The paper presents the construction of frames, types of packets and procedures for the authentication, assignment of time slots available to the node, releasing assigned slots and slots assignment conflict detection.
-
Ultrawideband transmission in physical channels: a broadband interference view
PublikacjaThe superposition of multipath components (MPC) of an emitted wave, formed by reflections from limiting surfaces and obstacles in the propagation area, strongly affects communication signals. In the case of modern wideband systems, the effect should be seen as a broadband counterpart of classical interference which is the cause of fading in narrowband systems. This paper shows that in wideband communications, the time- and frequency-domain...
-
Transmission and reflection coefficients for damage identification in 1D elements
PublikacjaW pracy przedstawiono mozliowści wykorzystania współczynnika odbicia i przejścia fali sprężystej w miejscu nieciągłości konstrukcji do identyfikacji jej rodzaju
-
Wave transmission across surface interfaces in lattice structures
PublikacjaWithin the lattice dynamics formulation, we present an exact solution for anti-plane surface waves in a square lattice strip with a surface row of material particles of two types separated by a linear interface. The considered problem is a discrete analog of an elastic half-space with surface stresses modelled through the simplified Gurtin–Murdoch model, where we have an interfacial line separating areas with different surface...
-
Study Analysis of Transmission Efficiency in DAB+ Broadcasting System
PublikacjaDAB+ is a very innovative and universal multimedia broadcasting system. Thanks to its updated multimedia technologies and metadata options, digital radio keeps pace with changing consumer expectations and the impact of media convergence. Broadcasting analog and digital radio services does vary, concerning devices on both transmitting and receiving side, as well as content processing mechanisms. However, the biggest difference is...
-
Numerical Issues and Approximated Models for the Diagnosis of Transmission Pipelines
PublikacjaThe chapter concerns numerical issues encountered when the pipeline flow process is modeled as a discrete-time state-space model. In particular, issues related to computational complexity and computability are discussed, i.e., simulation feasibility which is connected to the notions of singularity and stability of the model. These properties are critical if a diagnostic system is based on a discrete mathematical model of the flow...
-
Influence of the thermal modernization of window on transmission heat losses
PublikacjaThe article presents the results of calculations of the heat transfer coefficient for the state before and after renovation for the historic windows. The aim of the analysis was to obtain the values of thermal insulation parameters demanded by the regulations, while not losing the historical value of the window. The described example of the renovation of the existing window consisted in installing an additional window panel from...
-
Research on Quality Requirements of Data Transmission Services in RSMAD
PublikacjaThe paper presents a results and analysis of research of the quality of service requirements (defined by the QoS attributes) for imaging data transmission services using Radio System for Monitoring and Acquisition of Data from Traffic Enforcement Cameras (in short RSMAD). The paper also presents and discusses results of test on the impact of the size of photos from traffic enforcement cameras on the average transmission time. These...
-
Application of OFDM technique to underwater acoustic data transmission
PublikacjaPerformances of underwater acoustic communication (UAC) digital systems are strongly related to specific transmission properties of the underwater channel. Depending on the characteristics of the channel, an architecture and modulation techniques are usually implemented that are known as reliable solutions for data transmission in difficult radio channels. The OFDM technique seems to be the most promising nowadays. The parameters...
-
Digital Fingerprinting based on Quaternion Encryption for Image Transmission
PublikacjaIn this paper a new digital fingerprinting scheme for images is proposed. A proposed method is based on quaternion encryption with Cipher Block Chaining (CBC) mode of operation. Quaternions are hyper-complex numbers of rank 4 and thus often applied to mechanics in three-dimensional space. The encryption algorithm is designed for grey-tone images. For purpose of encryption, the algorithm uses the rotation of data vectors presented...
-
Wireless data transmission for fiber optical sensor system
PublikacjaW artykule opisano możliwość wykorzystania bezprzewodowego systemu transmisji danych do transmisji sygnałów z czujników światłowodowych.
-
A quaternion-based modified feistel cipher for multimedia transmission
PublikacjaIn this paper a quaternion-based modified Feistel Cipher is proposed. The algorithm is based on the scheme proposed by Sastry and Kumar (2012). Our algorithm uses special properties of quaternions to perform rotations of data sequences in 3D space for each of the cipher rounds. The plaintext (image in gray-tone) is divided into two square matrices of equal size which consist of Lipschitz quaternions. A modular arithmetic was implemented...
-
Board cross-section errors while sawing on twin shaft multi-rip saws
PublikacjaW pracy przedstawiono wpływ warunków pracy pił na powstawanie błędów przecinania w postaci uskoku na przekroju poprzecznym tarcicy.
-
Influence of bush wear in water lubricated marine stern tube bearings with shaft misalignment
PublikacjaWater lubricated propeller shaft bearings are frequently employed on modern ships due to their advantages such as durability, simplicity and low price. Specific working conditions on ships cause shaft misalignment which often results in rapid wearing of bush and shaft. Shaft misalignment could be an effect of manufacturing or assembly faults but sometimes it appears due to hull or shaft deformation. The wearing process has influence...
-
Multistage Coupling of Eight Mistuned Bladed Disk on a Solid Shaft, Forced Vibration Analysis
Publikacja -
Numerical estimation of the pile toe and shaft unit resistances during the installation process in sands
PublikacjaNumerical simulations of a pile jacking were carried out. A Coupled Eulerian–Lagrangian (CEL) formulation was used to treat with large deformation problems. An Abaqus, a commercial Finite Element Method software suit, was used as a computing environment. The Mohr–Coulomb constitutive model was applied and the Coulomb model of friction was used to describe pile-soil interaction. Calculations were made for three different pile diameters....
-
Influence of Bearing Bush Geometry on Properties of Water Lubricated Marine Main Shaft Bearings
PublikacjaW pracy przedstawiono wpływ geometrii smarowanego wodą, okrętowego łożyska ślizgowego wału głównego na jego własności hydrodynamiczne.Wykazano, że wielkość luzu łożyskowego, położenie oraz liczba rowków smarnych mają znaczący wpływ na nośnosć łożyska.
-
Influence of main design parameters of ship propeller shaft water-lubricated bearings on their properties
PublikacjaW artykule omówiono wpływ głównych parametrów konstrukcyjnych i eksploatacyjnych takich jak wielkość luzu łożyskowego, własności materiału panwi, stanu powierzchni skojarzenia ślizgowego oraz temperatury i zasolenia wody na nośność hydrodynamiczną łożyska okrętowego wału śrubowego smarowanego wodą.
-
Air journal bearing utilizing near-field acoustic levitation: stationary shaft case
PublikacjaResults of a study to examine a unique idea of self-levitating journal bearing are presented in this paper. the idea represents a radical departure from the current bearing technology. it utilisesacoustic levitation, which relies on the sound energy radiated by an object supporting a load. acoustic levitation has been demonstrated to support loads of up to 10 kg. in order to support a load theacoustic wave emitted by the radiating...
-
The concept of estimation of elevator shaft control measurement results in the local 3D coordinate system.
PublikacjaGeodetic control measurements play an important part because they provide information about the current state of repair of the construction, which has a direct impact on the safety assessment of its exploitation. Authors in this paper have focused on control measurements of the elevator shaft. The article discusses the problem of determining the deviation of elevator shaft walls from the vertical plane in the local 3D coordinate...
-
Optimisation of turbine shaft heating process under steam turbine run-up conditions
PublikacjaAn important operational task for thermal turbines during run-up and run-down is to keep the stresses in the structural elements at a right level. This applies not only to their instantaneous values, but also to the impact of them on the engine lifetime. The turbine shaft is a particularly important element. The distribution of stresses depends on geometric characteristics of the shaft and its specific locations. This means a groove manufactured...
-
Estimating of the rough green target size in lumber manufacturing on the twin shaft multi-rip saws
PublikacjaW pracy przedstawiono analizę i wyniki badań doświadczalnych dokładności przecinania pryzm ze zmrożonego drewna brzozowego na dwuwrzecionowej pilarce tarczowej w warunkach przemysłowych. W badaniach wykorzystywano piły typu "Multix" oraz piły nowego typu. Ponadto, wykazano, że obecność w przekroju poprzecznym, zmiennego na długości przecinanej deski, stopnia po obu jej stronach ma znaczny wpływ na szacowanie wymiaru początkowego...
-
Shaft Misalignment Influence on Water Lubricated Turbine Sliding Bearings with Various Bush Modules of Elasticity
PublikacjaW artykule przeanalizowano wpływ wielkości przenoszenia osi wału względem panwi na nośność łożyska. Analizie poddano łożyska z odmiennymi rodzajami panwi o różnej sztywności.
-
Marine propeller shaft bearings under low-speed conditions: water vs. oil lubrication
PublikacjaThe bearings used in shipbuilding, hydropower, and water pumps have undergone a metamorphosis in recent decades. Because of environmental regulations, lubrication with grease or mineral oil is prohibited. Thus, the standard solutions include water-lubricated bearings with polymer bushings or sealed systems lubricated with oil. When properly designed, assembled, and operated, bearings can operate reliably for years. However, specific...
-
WATER LUBRICATED MAIN SHAFT BEARINGS - MODERN SOLUTION FOR HYDROPOWER INDUSTRY - Experimental and theoretical studies
PublikacjaWater-lubricated bearings are finding increasingly wide use in various branches of industry. As such, they may also be encountered in hydro power industry. They are also increasingly frequently employed in bearing systems of marine shaft propulsions and water pumps [1]. This rising popularity is due to a number of reasons [2]. First of all, their simple construction has direct impact on the level of pricing which is usually quite...
-
Assessment of possible application of water lubricated sintered brass slide bearing for marine propeller shaft
PublikacjaW artykule przedstawiono wyniki badań eksperymentalnych smarowanego wodą łożyska poprzecznego z panwią wykonaną ze spieku brązu.Przedstawiono wyniki pomiarów rozkładu ciśnienia w filmie smarnym, trajektorie osi wału oraz oporów ruchu.Przeprowadzono ocenę przydatności tego typu łożyska do łożyskowania okrętowych wałów śrubowych.
-
The effect of the power transmission of the spindle on the position of the circular saw teeth
PublikacjaNa dokładność przecinania ma decydujący wpływ położenie ostrzy piły tarczowej. W pracy analizowano przyczyny i błędy połozenia ostrzy piły w stosunku do przedmiotu obrabianego spowodowane odkształceniem wrzeciona wywołanym przez siły skrawania i siły pochodzące od napędu.
-
Measurement accuracy evaluation of transmission line earthings by impulse tests
PublikacjaUziemienia słupów linii energetycznych powinny być sprawdzane okresowo. Pomiary rezystancji takich uziemień przy pomocy metody niskoczęstotliwościowej wymaga wyłaczania linii i odkręcania przewodów odprowadzających od konstrukcji słupa. Metoda udarowa jest znacznie łatwiejsza w tej aplikacji i nie wymaga wyłaczania linii na czas pomiarów. W pracy oszacowano wpływ uziemień sąsiednich słupów na dokładność pomiarów metodą udarową.
-
Approximate models and parameter analysis of the flow process in transmission pipelines
Publikacjathe paper deals with the problem of early leak detection in transmission pipelines. First we present the derivation of state-space equations of the flow process in the pipelines. This description is then aggregated in order to obtain a principal model. Next, the problem of process model parameterization is addressed, taking into account the maximization of a model stability margin. The location of the maximum is determined using...
-
The Methodology of identifying the place to install shunt compensators in the transmission network
PublikacjaThis methodology of selection and localization of static com- paper presents pensators in wide network. Proposed method is based on analysis of voltage area power profiles in the nodes of the power grid, and designating locations, In Which Voltages ex- cessively tend to change in time. Practical way of modeling the SVC device in PLANS program you Presented, as well as some example results of research.
-
Secure transmission of visual image in the VTS system using fingerprinting
Publikacja -
The Issues of Reactive Power Compensation in High-voltage Transmission Lines
PublikacjaThis paper discusses the selection of compensation shunt reactors for a double-circuit 400 kV transmission line using the example of the newly built Elk Bis – Alytus transmission line. The analysis takes into account various conditions of the power system. The published results relate to voltage levels in steady states and during switching processes and short circuits.
-
Establishment of the Right of Electricity Transmission Easement Through Court Proceedings
PublikacjaIncluding the amendment of the Civil Code Act on May 30, 2008, issues related to the right of easement of transmission were introduced to it. Such a regulation was necessary in view of the need to define the legal status of transmission facilities, existing and designed on real estate property. The purpose of the study is to analyze issues related to the definition of the spatial extent of the law of transmission easement for power...
-
Reduction of Computational Complexity in Simulations of the Flow Process in Transmission Pipelines
PublikacjaThe paper addresses the problem of computational efficiency of the pipe-flow model used in leak detection and identification systems. Analysis of the model brings attention to its specific structure, where all matrices are sparse. With certain rearrangements, the model can be reduced to a set of equations with tridiagonal matrices. Such equations can be solved using the Thomas algorithm. This method provides almost the same values...
-
Simulation of Signal Propagation Along Fractional-Order Transmission Lines
PublikacjaIn this paper, the simulation method of signal propagation along fractional-order (FO) transmission lines is presented. Initially, fractional calculus and the model of FO transmission line are introduced. Then, the algorithm allowing for simulation of the nonmonochromatic wave propagation along FO transmission lines is presented. It employs computations in the frequency domain, i.e., an analytical excitation is transformed to the...
-
Selective jamming of OFDM transmission in NB-IoT radio interface
PublikacjaThe paper presents the concept of smart jamming, which involves selective interference aimed at critical components of the OFDM signal. Research verifying the feasibility of this type of electronic attack are described. A realized testbed for jamming real NB-IoT signals in a downlink is presented. The test results demonstrate the feasibility of realizing selective jamming and its greater effectiveness compared to barrage interference.
-
Transmission Quality in MC-CDMA Radio Interface with Turbo Codes
PublikacjaMulti-Carrier Code Division Multiple Access techiques is a combination of two radio access techniques: Code Division Multiple Access (CDMA) and Orthogonal Frequency-called Division Multiplexing (OFDM) and has the advantages of both techniques. The paper presents the design of transmitter and receiver for MC-CDMA radio interface and the simulation results of the transmission quality in AWGN channel.
-
Testing OFDM Transmission Schemes for Shallow Water Acoustic Communications
PublikacjaLarge variability of communication properties of underwater acoustic channels, and especially strongly varying instantaneous conditions in shallow waters, is a tough challenge for the designers of underwater acoustics communication (UAC system. There is a need for developing adaptive signaling schemes that would dynamically optimize signal parameters in both physical and link layers of communication protocols. The orthogonal frequency...
-
Transmission protocol simulation framework for the resource-constrained sensor network
PublikacjaIn this paper the simulation framework for simulation of the sensor network protocol is presented. The framework enables the simultaneous development of the sensor network software and the protocol for the wireless data transmission. The advantage of using the framework is the convergence of the simulation with the real software, because the same software is used in real sensor network nodes and in the simulation framework. The...
-
Quaternion encryption methods for multimedia transmission, a survey of existing approaches
PublikacjaIn this paper we review quaternion encryption methods for multimedia transmission. We explain their weak and strong properties as well as suggest possible modifications. Our main focus is an algorithm QFC presented in paper by Dzwonkowski et al. (2015). All encryption methods, presented in this paper, use special properties of quaternions to perform rotations of data sequences in 3D space. Each method uses a common key generation...
-
MEASUREMENT AND ANALYSIS OF TRANSMISSION LOSSES IN THE SUPPLY SYSTEM OF ELECTRIFIED TRANSPORT
PublikacjaThe issue of electric energy saving in public transport is currently becoming a key area of interest, a fact connected with both an increase in society’s environmental awareness and a rise in the prices of fuel and electricity. Electricity can be saved by reducing transmission losses in the supply system. The article presents a method of measurement and analysis of transmission losses in the supply system of electrified public transport...
-
Square-wave propagation along coupled coplanar transmission line.
PublikacjaW pracy przedstawiono wyniki modelowania propagacji fali prostokątnej w układzie sprzężonych linii koplanarnych z uziemionym centralnym paskiem. Przeanalizowano napięcia przesłuchów na bliskim i dalekim końcu linii sprzężonych wykazując poprawę zgodności wyników modelowania i eksperymentu przy uwzględnieniu propagacji wielomodowej.
-
WATER LUBRICATED MAIN SHAFT BEAR INGS WITH THREE LAYER BUSH – MODERN SOLUTION FOR MARINE INDUSTRY
PublikacjaWater lubricated sliding bearings are increasingly popular in marine and hydro power industry. Such popularity is partly due to their simple construction which also means a relatively affordable price. Properly designed and installed water lubricated bearings may well last for over a decade. During the last decade their traditional range has been expanded with new, modern products like three layer bearing bush. The work presents...
-
Multistage Coupling of Eight Mistuned Bladed Disk on a Solid Shaft, Part 1 Free Vibration Analysis
Publikacja..
-
Multistage Coupling of Eight Mistuned Bladed Discs on Solid Shaft, in book: Recent Advances in Rotor Dynamic
Publikacja -
ENERGY ANALYSIS OF THE PROPULSION SHAFT FATIGUE PROCESS IN A ROTATING MECHANICAL SYSTEM PART III DIMENSIONAL ANALYSIS
PublikacjaThis article presents the third and last part of the problem of diagnosing the fatigue of marine propulsion shafts in terms of energy with the use of the action function, undertaken by the authors. Even the most perfect physical models of real objects, observed under laboratory conditions and developed based on the results of their research, cannot be useful in diagnostics without properly transferring the obtained results to the...
-
Design of Analog Filters with Single Transmission Zeros, Dedicated for HFB Systems
Publikacja -
Spillover and risk transmission in the components of the term structure of eurozone yield curve
Publikacja -
<title>Intranet and Internet metrological network with photonic sensors and transmission</title>
Publikacja